“…For example, a number of studies have found that air pollution exposure could be impacted by small-scale differences in the built environment, including traffic and road geometry [ 67 ], impervious surface [ 68 , 69 ], greenness [ 70 ], walkability [ 71 ], the fragmentation of urban patches [ 70 ], and other factors [ 19 , 72 , 73 , 74 ]. Oftentimes, disadvantaged communities are near highways, have much fewer green spaces, much greater auto dependence, poor quality pavement streets, and residential segregation patterns [ 14 , 46 , 48 ], which may be associated with adverse air pollution exposure [ 73 ] and disparities [ 75 ]. Without increased air monitoring networks among disadvantaged communities, one cannot explore such mechanisms, thus failing to eliminate built environment disparities [ 76 ], conduct air pollution exposure assessment [ 77 ], inform emission control strategies [ 43 ], and assess public health outcomes [ 6 ].…”